Question: $ { \left[\begin{array}{rr}{-2} & {1} \\ {4} & {-1} \\ {1} & {4}\end{array}\right]+\left[\begin{array}{rr}{-1} & {4} \\ {3} & {1} \\ {1} & {4}\end{array}\right] = {?} } $
To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rr}{-2}+{-1} & {1}+{4} \\ {4}+{3} & {-1}+{1} \\ {1}+{1} & {4}+{4}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{-3} & {5} \\ {7} & {0} \\ {2} & {8}\end{array}\right]}$